Internal combustion engines have associated fluid systems for cooling and lubrication. Often the fluid jackets or passages are integrally formed within the cylinder block (or crankcase) and/or cylinder head of the engine. The shape of the jacket and passages may be dependent on or limited by the manufacturing method used to form them.
For example, with a conventional die casting process and an open deck cylinder block, the cylinder block may be formed using free standing cylinder liners with the inner bores connected in a siamese configuration and a cooling jacket surrounding the liners. The cooling jacket typically has a smooth contour and is limited in its depth to fit between the head bolt column and bore wall. The draft angle on the cooling jacket is uniform and straight to allow for the dies to open after casting. This draft angle and the manufacturing process does not allow for a complex structure in the jacket to create flow dynamics for coolant mixing while coolant flows through the jacket. Additionally, the casting process typically does not allow for the formation of interbore cooling passages, and the like, and these passages are typically formed after casting using a machining process such as drilling.
In another example, in a conventional sand casting process, the cylinder block may be formed with an open deck or a closed deck. The sand casting process may limit the shape of fluid jackets, as the sand forms may be required to have certain minimum thicknesses to survive the casting process. Sand casting may also limit the arrangement of the deck face around the cylinders and head bolt columns. For example, if the interbore bridge is less than twelve millimeters, a sand cast interbore cooling passage will not be able to be packaged within the space.
The manufacturing processes, and resulting fluid jacket structure, may limit the control of the flow characteristics, control over heat transfer, and control over the engine temperature. For example, the cooling jacket may limit the control over the temperature and thermal gradient in the cylinder wall, bore wall, or liner.
A fluid jacket formed using a mono blade in a one contiguous shape with a die casting produces a water jacket that may not allow for reduced volumes and features that do not allow fluid to flow in a layered parallel path, nor allow a uniform bore wall temperature to be realized. This may also be said about a sand cast produced water jacket.